This invention relates to plastic injection machines, and, more particularly, to a flow regulating assembly for restricting plastic material from flowing directly into an accumulator cavity of a plastic injection machine and instead directing the plastic material towards the wall of the accumulator cavity thereby providing a scouring effect and reducing the build-up of the plastic material on the wall of the accumulator cavity.
Center feed plastic injection machines are known in the art in which plastic material is allowed to flow through a central cavity of an injection piston and into an accumulator cavity, prior to displacement of the plastic material by the injection piston through an injection nozzle and into a mold unit. In these devices, the plastic material flows directly into the accumulator cavity.
The problem with direct flow of the plastic material from the central cavity of the injection piston to the central portion of the accumulator cavity is that this results in uneven flow. Furthermore, when the plastic material flows directly into the central portion of the accumulator cavity, this leaves a certain amount of area on either side of the central chamber/accumulator cavity interface where the plastic material does not flow. These areas are commonly known as "dead corners" where stagnant plastic material can build-up and effect the plastic injection process. After a certain amount of build-up, the accumulator cavity must be cleaned to remove this hardened plastic material which is labor intensive and time consuming resulting in high cost over time. Producing a more even continuous flow during the process and reducing the labor and time involved in removing the build-up plastic material is, accordingly, desirable.
The difficulties in the prior art plastic injection systems are substantially eliminated by the present invention.